It is well known in the prior art to employ extension devices in association with ladders incorporating two side rails. Typically, the extension device is connected to one of the rails and is employed to level the side rails of the ladder when the ladder is utilized on an uneven surface. Examples of such arrangements are shown in the following United States patents: U.S. Pat. No. 2,783,928, issued Mar. 5, 1957, U.S. Pat. No. 5,507,364, issued Apr. 16, 1996, U.S. Pat. No. 5,553,963, issued Sep. 10, 1996, U.S. Pat. No. 973,509, issued Oct. 25, 1910, U.S. Pat. No. 5,609,222, issued Mar. 11, 1997, U.S. Pat. No. 5,174,412, issued Dec. 29, 1992, U.S. Pat. No. 4,984,655, issued Jan. 15, 1991, and U.S. Pat. No. 2,542,398, issued Feb. 20, 1951.
As mentioned above, such devices are employed to level conventional ladders incorporating two side rails by adjusting the side-to-side orientation of the ladder to accommodate different support levels such as changes in ground height. The devices disclosed in the above-identified patents are not employed with a stepladder to maintain the rung side of the stepladder at substantially the same elevation as the step side thereof when the step side is located on a surface that is elevated relative to the surface which will support the rung side of the stepladder. Furthermore, many prior art approaches are characterized by their relative complexity, high expense and difficulty of adjustment and use.
My co-pending U.S. patent application Ser. No. 09/141,661, filed Aug. 28, 1998, discloses apparatus which supports and elevates the rung side of a stepladder to maintain the rung side and step side of the stepladder at substantially the same level.
The invention disclosed and claimed herein is for the same purpose.